The Papworth Experience With the Levitronix CentriMag Ventricular Assist Device

Temporary Mechanical Circulatory Support after Cardiac Surgery

Postcardiotomy shock in the cardiac surgical patient is a highly morbid condition characterized by profound myocardial impairment and decreased systemic perfusion inadequate to meet end-organ metabolic demand. Postcardiotomy shock is associated with significant morbidity and mortality. Poor outcomes motivate the increased use of mechanical circulatory support (MCS) to restore perfusion in an effort to prevent multiorgan injury and improve patient survival. Despite growing acceptance and adoption of MCS for postcardiotomy shock, criteria for initiation, clinical management, and future areas of clinical investigation remain a topic of ongoing debate. This article seeks to (1) define critical cardiac dysfunction in the patient after cardiotomy, (2) provide an overview of commonly used MCS devices, and (3) summarize the relevant clinical experience for various MCS devices available in the literature, with additional recognition for the role of MCS as a part of a modified approach to the cardiac arrest algorithm in the cardiac surgical patient.

Intraoperative prophylactic right ventricular assist device in prevention of postcardiotomy failure

OBJECTIVES

In patients at risk of developing right ventricular failure after cardiac surgery, right ventricular support with a ventricular assist device may be a promising strategy to reduce mortality. We present our experience with intraoperative right ventricular assist device implantation as a prevention strategy of right ventricular failure after cardiac surgery.

METHODS

Between 2016 and 2022, we implanted four right ventricular assist devices prophylactically in a series of patients with surgical indication for valvular heart disease and high risk of postoperative right ventricular failure. Indications for the right ventricular assist device were suprasystemic pulmonary hypertension or severe right ventricular dysfunction.

RESULTS

Externalization of the device cannulas through intercostal spaces was performed in three patients, allowing early mobilization and withdrawal without resternotomy. Removal of the device ocurred on the eighth postoperative day. ICU and hospital length of stay was 12 (±1.6) and 23 days (±4.2) respectively. Hospital mortality was null. No patient died during follow-up, mean follow-up was 32.5 months [1-72]. Patients improved their NYHA functional class up to grade II during follow-up.

CONCLUSIONS

Acute right ventricular failure after cardiac surgery remains a significant cause of morbidity and mortality. Prophylactic strategies to prevent postoperative right ventricular dysfunction may decrease the incidence of refractory postoperative right ventricular failure. We propose a novel approach to prevent right failure after cardiac surgery with prophylactic intraoperative ventricular assist device implantation.

Test Bench for Right Ventricular Failure Reversibility: The Hybrid BiVAD Concept

BACKGROUND

When heart transplantation and myocardial recovery are unlikely, patients presenting with biventricular cardiogenic shock initially treated with extracorporeal membrane oxygenation (ECMO) may benefit from a mechanical support upgrade. In this scenario, a micro-invasive approach is proposed: the combination of the double-lumen ProtekDuo cannula (Livanova, London, UK) and the Impella 5.5 (Abiomed, Danvers, MA) trans-aortic pump that translates into a hybrid BiVAD.

METHODS

All consecutive ECMO patients presenting with biventricular cardiogenic shock and ineligibility to heart transplantation from August 2022 were prospectively enrolled. The clinical course, procedural details, and in-hospital events were collected via electronic medical records.

RESULTS

A total of three patients, who were temporarily not eligible for heart transplantation or durable LVAD due to severe acute pneumonia and right ventricular (RV) dysfunction, were implanted with a hybrid BiVAD. This strategy provided high-flow biventricular support while pulmonary function ameliorated. Moreover, by differentially sustaining the systemic and pulmonary circulation, it allowed for a more adequate reassessment of RV function. All the patients were considered eligible for isolated durable LVAD and underwent less invasive LVAD implantation paired with a planned postoperative RVAD. In all cases, RV function gradually recovered and the RVAD was successfully removed.

CONCLUSIONS

The Hybrid BiVAD represents an up-to-date micro-invasive mechanical treatment of acute biventricular failure beyond ECMO. Its rationale relies on more physiological circulation across the lungs, the complete biventricular unloading, and the possibility of including an oxygenator in the circuit. Finally, the independent and differential control of pulmonary and systemic flows allows for more accurate RV function evaluation for isolated durable LVAD eligibility reassessment.

Heart Transplantation and Thromboembolic Risk In Patients With Percutaneous Aortic Valve Prosthesis and Left Ventricular Assist Device: A Case Report

Transcatheter aortic valve replacements have become a good option for patients with aortic valve disease and high surgical risk. Thromboembolism is reported as a relatively common complication of Transcatheter aortic valve replacement. This risk may be increased in patients who have left ventricular assist devices, as valve motion is drastically reduced. We present the case of a 65-year-old man with a history of alcoholism and valvular cardiomyopathy (severe chronic aortic insufficiency) with severe left ventricular dysfunction. Improvement in ventricular function followed the cessation of alcohol consumption, but still in poor clinical condition. Due to his high surgical risk, it was decided to implant a percutaneous aortic valve to treat the valve deficiency. Two months later, he suffered from a first episode of embolic stroke, which he successfully recovered. Despite the treatment, his clinical status did not improve (INTERMACS 3-4), and he was referred for heart transplantation. A left ventricular assist device was implanted as a bridge to the transplant. While on the waiting list, he suffered from other 3 episodes of stroke, 2 of them requiring mechanical thrombectomy. Finally, his transplant was performed with a favorable postoperative clinical course. Heart transplantation may be feasible in patients with multiple intracardiac devices in left chambers, although we must be aware of the increased thromboembolic risk, especially when used in combination.

Extracorporeal Life Support and Temporary CentriMag Ventricular Assist Device to Salvage Cardiogenic-Shock Patients Suffering from Prolonged Cardiopulmonary Resuscitation

Background: The extracorporeal life support (ECLS) and temporary bilateral ventricular assist device (t-BiVAD) are commonly applied in patients with cardiogenic shock. Prolonged cardiopulmonary resuscitation (CPR) has poor prognosis. Herein, we report our findings on a combined ECLS and t-BiVAD approach to salvage cardiogenic-shock patients with CPR for more than one hour. Methods: Fifty-nine patients with prolonged CPR and rescued by ECLS and subsequent t-BiVAD were retrospectively collected between January 2015 and December 2019. Primary diagnoses included ischemic, dilated cardiomyopathy, acute myocardial infarction, post-cardiotomy syndrome, and fulminant myocarditis. The mean LVEF was 16.9% ± 6.56% before t-BiVAD. The median ECLS-to-VAD interval is 26 h. Results: A total of 26 patients (44%) survived to weaning, including 13 (22%) bridged to recovery, and 13 (22%) bridged to transplantation. Survivors to discharge demonstrated better systemic perfusion and hemodynamics than non-survivors. The CentriMag-related complications included bleeding (n = 22, 37.2%), thromboembolism (n = 5, 8.4%), and infection (n = 4, 6.7%). The risk factors of mortality included Glasgow Coma Scale (Motor + Eye) ≤ 5, and lactate ≥ 8 mmol/L at POD-1, persistent ventricular rhythm or asystole, and total bilirubin ≥ 6 mg/dL at POD-3. Mortality factors included septic shock (n = 11, 18.6%), central failure (n = 10, 16.9%), and multiple organ failure (n = 12, 20.3%). Conclusions: Combined ECLS and t-BiVAD could be a salvage treatment for patients with severe cardiogenic shock, especially for those already having prolonged CPR. This combination can correct organ malperfusion and allow sufficient time to bridge patients to recovery and heart transplantation, especially in Asia, where donation rates are low, as well as intracorporeal VAD or total artificial heart being seldom available.

Long term CentriMag biventricular support using hybrid cannulation as a bridge to transplant in a pediatric patient

Paracorporeal continuous-flow ventricular assist devices designed for short-term support can also potentially provide long-term circulatory support as bridges to transplantation in children. We describe the long-term use of the CentriMag biventricular assist device with multiple pump changes in a 9-year-old boy with idiopathic-dilated cardiomyopathy. The initially implanted Berlin Heart EXCOR pumps were replaced by CentriMag due to thromboembolic complications. The CentriMag pumps were exchanged 15 times due to clot and fibrin formation or when the pumps reached their expiration dates. Connecting CentriMag to Berlin Heart EXCOR cannulae effectively served as an alternative long-term hybrid bridge to transplantation for 235 days. The patient successfully underwent a transplant after 284 days. Judicious pump monitoring and timely pump exchanges can potentially overcome device-related complications and extend the duration on support.

Choosing Between Left Ventricular Assist Devices and Biventricular Assist Devices

Right ventricular failure following left ventricular assist devices implantation is a serious complication associated with high mortality. In patients with or at high risk of developing right ventricular failure, biventricular support is recommended. Because univentricular support is associated with high survival rates, biventricular support is often undertaken as a last resort. With the advent of newer right ventricular and biventricular systems under design and testing, better differentiation is required to ensure optimal patients care. Clear guidelines on patient selection, time of intervention and device selection are required to improve patient outcomes.

Aortic Valve Thrombosis after Valve-Sparing Aortic Root Replacement and Insertion of an Extracorporeal Left Ventricular Assist Device, Masked by Mediastinal Packing

Aortic valve (AV) or aortic root thrombus related to a left ventricular assist device (LVAD) is a relatively uncommon but potentially life-threatening complication. In the present report, we describe a complex case where echocardiographic diagnosis of AV thrombosis was obscured by the presence of mediastinal packing in a patient who underwent valve-sparing aortic root replacement and insertion of the CentriMag™ LVAD for postcardiotomy cardiogenic shock. A large AV thrombus may develop rapidly in patients with LVADs. This case highlights the importance of a careful and thorough transesophageal echocardiography examination in detecting this complication and in altering surgical management.

Utilization and Outcomes of Temporary Mechanical Circulatory Support for Graft Dysfunction After Heart Transplantation

Graft dysfunction is the main cause of early mortality after heart transplantation. In cases of severe graft dysfunction, temporary mechanical circulatory support (TMCS) may be necessary. The aim of this systematic review was to examine the utilization and outcomes of TMCS in patients with graft dysfunction after heart transplantation. Electronic search was performed to identify all studies in the English literature assessing the use of TMCS for graft dysfunction. All identified articles were systematically assessed for inclusion and exclusion criteria. Of the 5,462 studies identified, 41 studies were included. Among the 11,555 patients undergoing heart transplantation, 695 (6.0%) required TMCS with patients most often supported using venoarterial extracorporeal membrane oxygenation (79.4%) followed by right ventricular assist devices (11.1%), biventricular assist devices (BiVADs) (7.5%), and left ventricular assist devices (LVADs) (2.0%). Patients supported by LVADs were more likely to be supported longer (p = 0.003), have a higher death by cardiac event (p = 0.013) and retransplantation rate (p = 0.015). In contrast, patients supported with BiVAD and LVAD were more likely to be weaned off support (p = 0.020). Overall, no significant difference was found in pooled 30 day survival (p = 0.31), survival to discharge (p = 0.19), and overall survival (p = 0.51) between the subgroups. Temporary mechanical circulatory support is an effective modality to support patients with graft dysfunction after heart transplantation. Further studies are needed to establish the optimal threshold and strategy for TMCS and to augment cardiac recovery and long-term survival.

A dual therapy of off-pump temporary left ventricular extracorporeal device and amniotic stem cell for cardiogenic shock

Background

Temporary mechanical circulatory support device without sternotomy has been highly advocated for severe cardiogenic shock patient but little is known when coupled with amniotic stem cell therapy.

Case presentation

This case reports the first dual therapy of temporary left ventricular extracorporeal device CentriMag with distal banding technique and human amniotic stem cell injection for treating a severe refractory cardiogenic shock of an 68-year-old female patient. A minimally-invasive off-pump LVAD was established by draining from the left ventricle and returning to the right axillary artery with distal arterial banding to prevent right upper extremity hyperperfusion. Amniotic stem cells were injected intramyocardially at the left ventricular apex, lateral wall, inferior wall, and right subclavian vein.

Conclusion

The concomitant use of the temporary minimally-invasive off-pump CentriMag placement and stem cell therapy not only provided an alternative to cardiopulmonary bypass and full-median sternotomy procedures but may have also synergistically enhanced myocardial reperfusion and regeneration.

Bridge to transplant or recovery in cardiogenic shock in a developing country

Background Durable mechanical support devices are prohibitively expensive in our health system and may be unsuitable for critically ill patients. CentriMag is an alternative bridge to transplantation or recovery. Methods We retrospectively reviewed 28 patients (23 males) aged 13-60 years who received CentriMag support. The etiology was ischemic in 13 (46%), dilated cardiomyopathy in 8 (29%), and others in 7 (25%). All patients were in Interagency Registry for Mechanically Assisted Circulatory Support class I, and 27 (96%) had multiorgan failure; 2 (7%) were post-cardiotomy and 12 (43%) had a previous cardiac arrest (mean arrest time 21 ± 17 min). Results Thirty-day post-implant survival was 79% (22 patients). Twenty (71%) patients were successfully bridged to transplantation or recovery. The mean support time was 40 days; 12 (43%) patients had >4-weeks' support (longest was 292 days). Eight (29%) patients died on support. Complications included bleeding in 10 (36%) cases, immediate stroke in 4 (14%), and dialysis in 8 (29%). There was no stroke during subsequent support. Eighteen (64%) patients underwent transplantation, and 17 of them were discharged. Two (7%) patients recovered and were discharged. Two-year survival was 62% ± 10%. Mean follow-up was 21 months (total follow-up 579 months). Two (7%) patients died during follow-up. All survivors were in New York Heart Association class I. Conclusions CentriMag is useful for medium-term support for cardiogenic shock in a developing country. Support for >4 weeks is feasible. The stroke rate is low during support. The major drawback is prolonged intensive care unit stay.

Neurologic Complications in the Intensive Care Unit

Complications involving the central and peripheral nervous system are frequently encountered in critically ill patients. All components of the neuraxis can be involved including the brain, spinal cord, peripheral nerves, neuromuscular junction, and muscles. Neurologic complications adversely impact outcome and length of stay. These complications can be related to underlying critical illness, pre-existing comorbid conditions, and commonly used and life-saving procedures and medications. Familiarity with the myriad neurologic complications that occur in the intensive care unit can facilitate their timely recognition and treatment. Additionally, awareness of treatment-related neurologic complications may inform decision-making, mitigate risk, and improve outcomes.

Short-Term Ventricular Assist Device as a Bridge to Decision in Cardiogenic Shock: Is It a Justified Strategy?

Purpose

Low cardiac output syndrome is associated with significant mortality. In patients with refractory low cardiac output left ventricular assist devices (VAD) are used to re-establish cardiac output and to prevent death. However, long-term LVAD implantation in these is complicated by a high rate of right heart failure and mortality. Therefore, our strategy is to implant a short-term VAD (left or biventricular) as a bridge to decission.

Methods

We retrospectively analysed data from 66 patients who received a short-term LVAD support prior to implantation of a long-term LVAD or HTx between 2003 and 2014. We performed short-term LVAD (CentriMag; Thoratec) implantation via median sternotomy with percutaneous cannulas. Patients were included regardless of perioperative status and severity of heart failure. Patients suffering postcardiotomy cardiogenic shock, receiving isolated RVAD as well as posttransplant patients were excluded from this study.

Results

Mean duration of support in the survivor group was 35 ± 25 days versus 25 ± 25 days in the nonsurvivor group (n.s.), range from 1 to 109 days. The overall survival on support was 40 (60%) patients. In the survivor group 12 patients could be successfully weaned from the system, 12 patients received a heart transplant and in 16 a long-term VAD was implanted. In the nonsurvivor group the rate of pre-operative extracorporeal life support, the rate of postoperative renal failure and multiorgan failure was significantly higher.

Conclusions

Thanks to its capacity for full ventricular support, short-term univentricular or biventricular LevotronixCentriMag VAD currently represents an ideal solution for bridge-to-decision.

Ventricular Assist Devices in Pediatric Cardiac Intensive Care

OBJECTIVES

The objectives of this review are to discuss the process of patient and mechanical device selection, operative management, and postoperative care with a focus on the management of right ventricular failure, anticoagulation strategies, device-related infections and neurologic sequelae.

DATA SOURCES

MEDLINE, PubMed.

CONCLUSION

The number of patients with advanced heart failure due to either acquired or congenital heart disease continues to increase, necessitating in some mechanical circulatory support and in others cardiac transplantation. With a limited cardiac donor pool, mechanical circulatory support is playing a greater role in the management of this population. The perioperative morbidity associated with mechanical circulatory support has lessened with improved postoperative management strategies.

Biventricular mechanical support devices--clinical perspectives

Cardiac transplantation remains the optimal treatment for end stage heart failure in selected patients. However, the shortage of donor hearts, rigorous eligibility criteria and long waiting lists have increased the demand for alternative treatment strategies such as mechanical circulatory support. While many patients are adequately supported with left ventricular assist devices, frequently there is right heart failure or involvement of the right ventricle, requiring biventricular support. Pulsatile flow biventricular devices and total artificial hearts approved for temporary biventricular support have limitations including size, high rates of adverse events and restricted mobility which makes them unsuitable for long term support. A number of centres have reported dual continuous flow left ventricular assist devices as a means of supporting the left and right heart. This review will summarise the literature on the outcomes and complications from current biventricular support devices and assess the role of dual continuous flow VAD therapy, and the new continuous flow total heart replacement devices.

Building a bridge to save a failing ventricle: radiologic evaluation of short- and long-term cardiac assist devices

Heart failure is recognized with increasing frequency worldwide and often progresses to an advanced refractory state. Although the reference standard for treatment of advanced heart failure remains cardiac transplantation, the increasing shortage of donor organs and the unsuitability of many patients for transplantation surgery has led to a search for alternative therapies. One such therapy is mechanical circulatory support, which helps relieve the load on the ventricle and thereby allows it to recover function. In addition, there is increasing evidence supporting the use of mechanical devices as a bridge to recovery in patients with acute refractory heart failure. In this article, the imaging evaluation of various commonly used short- and long-term cardiac assist devices is discussed, and their relevant mechanisms of action and physiology are described. Imaging, particularly computed tomography (CT), plays a crucial role in preoperative evaluation for assessment of candidacy for implantation of a left ventricular assist device (LVAD) or total artificial heart (TAH). Also, echocardiography and CT are indispensable in assessment of complications associated with cardiac devices. Complications commonly associated with short-term assist devices include bleeding and malpositioning, whereas long-term devices such as LVADs may be associated with infection, pump thrombosis, and cannula malfunction, as well as bleeding. CT is also commonly performed for preoperative planning before LVAD or TAH explantation, replacement of a device or one of its components, and cardiac transplantation. Online supplemental material is available for this article.

Thoratec CentriMag for temporary treatment of refractory cardiogenic shock or severe cardiopulmonary insufficiency: a systematic literature review and meta-analysis of observational studies

The aim of the study was to systematically evaluate effect of CentriMag heart pump (Thoratec Corporation) as temporary ventricular assist device (VAD) and part of extracorporeal membrane oxygenation (ECMO) system on outcomes in patients with cardiac or cardiac-respiratory failure. A systematic search was conducted in five databases for the period 2003 to 2012. Fifty-three publications with data for 999 patients, supported with CentriMag, were included. In 72% studies, CentriMag was used as a VAD and in 25% as part of ECMO circuit. Mean duration of VAD support was 25.0 days in precardiotomy group, 10.9 days in postcardiac surgery cardiogenic shock group, 8.8 days in post-transplant graft failure and rejection group, and 16.0 days in post-LVAD placement right ventricular failure group. Survival on support was 82% (95% CI 70-92) for VAD support in precardiotomy cardiogenic shock indication, 63% (95% CI 46-78) in VAD support in postcardiac surgery cardiogenic shock indication, 62% (95% CI 46-76) in VAD support in post-transplant graft rejection or failure indication, and 83% (95% CI 73-92) in VAD support in post-LVAD placement right ventricular failure indication. CentriMag is an effective technology for temporary support of patients with cardiac and cardiorespiratory failure.

Lessons learned with the use of CentriMag as short-term ventricular assist device in a child

The CentriMag ventricular assist device is an extracorporeal, third-generation, continuous flow device. The rapidity and simplicity of operation along with low priming volume make it attractive for use in children with refractory heart failure. We report the successful use of CentriMag as a bridge to recovery in a child and discuss issues that are unique to its use in children.

[Noncardiological surgical procedure for patients implanted with a ventricular assist device. Anesthesiological management concepts]

BACKGROUND

The implantation of a ventricular assist device (VAD) is more frequently used as destination therapy of end-stage heart failure compared to the use of the device as bridge-to-transplantation, this results in an increasing number of noncardiac surgical procedures for patients implanted with a VAD.

OBJECTIVE

For these procedures, the anesthesia provider faces various device-related complications, such as an increased risk for bleeding complications, thromboembolism, hypotension, infections, mechanical device limitations, and right heart failure. Anesthesia care is challenging in this high-risk patient population and has significant implications on patient outcome.

CONCLUSION

More research is needed to determine specific guidelines for the anesthesiological management of VAD patients undergoing noncardiac surgical procedures. In this manuscript, device-related perioperative complications and concepts of anesthesia care for noncardiac procedures in patients implanted with a VAD are briefly reviewed.

A comparison study of haemolysis production in three contemporary centrifugal pumps

One challenge in providing extracorporeal circulation is to supply optimal flow while minimising adverse effects, such as haemolysis. To determine if the recent generation constrained vortex pumps with their inherent design improvements would lead to reduced red cell trauma, we undertook a study comparing three devices. Utilizing a simulated short-term ventricular assist circuit primed with whole human blood, we examined changes in plasma free haemoglobin values over a six-day period. The three pumps investigated were the Maquet Rotaflow, the Levitronix PediVAS and the Medos Deltastream DP3.This study demonstrated that all three pumps produced low levels of haemolysis and are suitable for use in a clinical environment. The Levitronix PediVAS was significantly less haemolytic than either the Rotaflow (p<0.05) or the DP3 (p<0.05). There was no significant difference in plasma free haemoglobin between the Rotaflow and the DP3 (p=0.71).

Can the temporary use of right ventricular assist devices bridge patients with acute right ventricular failure after cardiac surgery to recovery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Can the temporary use of right ventricular assist devices (RVADs) bridge patients to recovery who suffer acute right ventricular failure after cardiac surgery? More than 183 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Indications for surgical intervention included coronary artery bypass surgery, valve replacement, post-heart transplant and left ventricular assist device insertion. Significant reductions in central venous pressure (P = 0.005) and mean pulmonary artery pressures (P < 0.01) were reported during and after RVAD support. Furthermore, increases in right ventricular cardiac output (P < 0.05), right ventricular ejection fraction (P < 0.05), right ventricular stroke work (P < 0.05) and pulmonary artery oxygen saturations (P < 0.05) were also seen. Assessment by one study showed that on Day 7 after RVAD removal, the right ventricular ejection fraction had increased by up to 40%. Dynamic echocardiography studies performed before, during and after RVAD placement demonstrated that after RVAD implantation, right ventricular end-diastolic dimensions (P < 0.05) and right atrial dimensions decreased (P < 0.05) and right ventricular ejection fraction (P < 0.05) increased. Although several studies successfully weaned patients from an RVAD, there were several complications, including bleeding requiring surgical intervention. However, this may be reduced by using percutaneous implantation (bleeding incidence: 4 of 9 patients) rather than by a surgically implanted RVAD (bleeding incidence: 5 of 5 patients). However, mortality is higher in percutaneous RVAD patients rather than in surgical RVAD (80-44%) patients. Causes of death cited for patients on an RVAD included multiorgan failure, sepsis, thromboembolic events, reoccurring right heart failure and failure to wean due to persistent right ventricular failure. We conclude that RVADs have been successfully used to bridge patients to recovery after cardiac surgery; however, RVADs carry numerous risks and a high mortality rate.

Aortic cannula disruption following long-term LVAD support

The Levitronix CentriMag is approved in Europe for 30 days as uni- or biventricular support in acute heart failure as a bridge to recovery, bridge to heart transplantation or to a long-term left ventricular assist device (LVAD). We report the case of a patient who was supported with the same Levitronix CentriMag pump for 119 days without changing any components of the circuit or the pump head because of an anatomical condition which precluded the feasibility of pump exchange and who did not experience any mechanical failure of the impeller but eventually died due to the rupture of the cannulae. This is the first report of failure of paracorporeal short-term LVAD due to disruption of one cannula with a properly functioning pump.

Impact of pump replacement on outcome in advanced heart failure patients with left ventricular assist system

Pump thrombosis is one of the major adverse events associated with the use of a left ventricular assist system (LVAS) in patients with advanced heart failure. We investigated the clinical implication of pump replacement because of thrombus formation. This study included 87 patients who underwent implantation of a Nipro (Toyobo) pulsatile extracorporeal LVAS intended as a bridge to transplantation and were alive more than 3 months after implantation. The pump of this device is translucent, and daily evaluation for signs of thrombus formation was performed. Pump replacement was performed for significant thrombus formation that became visible. Data collection including demographics as well as hematologic values were performed 1 day before (baseline) and 3 months after implantation, and all patients were followed for 2 years or until death. At 3 months after LVAS implantation, 41 patients (47.1%) had undergone pump replacement because of pump thrombus. Baseline body surface area <1.63 m(2) was a significant predictor of pump replacement (hazard ratio [HR] 2.15, P = 0.04). At 3 months after implantation, there was a significantly higher incidence of stroke (P < 0.05) as well as a significantly greater decrease in body weight (F = 4.92, P = 0.03) in patients who underwent pump replacement as compared to those without. The 2-year mortality after implantation was 26.4%. Multivariate Cox regression analysis showed that pump replacement within 3 months after implantation was an independent predictor of mortality (HR 2.50, P = 0.03). In conclusion, pump replacement for thrombus formation may have a strong association with worse outcome. Our results reconfirm the clinical importance of device thrombus in the management of LVAS.

Mechanical circulatory support for cardiogenic shock

Cardiogenic shock (CS) is a syndrome of progressive depression of myocardial function with systemic hypoperfusion. It occurs due to various aetiologies such as acute myocardial infarction, myocarditis, acute decompensated heart failure and postcardiotomy. Cardiogenic shock carries poor prognosis, and medical therapy alone is not effective. Mechanical circulatory support is required to unload the ventricles, decrease the myocardial demand, prevent further injury, improve the coronary perfusion, stabilise the haemodynamics and maintain the end-organ perfusion before definitive interventions such as coronary reperfusion can take place. Currently, there are several methods of mechanical circulatory support. These include extracorporeal life support, paracorporeal or extracorporeal ventricular-assist devices, percutaneous ventricular assist devices, intra-aortic balloon counterpulsation and total artificial heart. In this review, we discuss the role of each of these circulatory support devices in the management of acute cardiac failure.

What is the optimal mode of mechanical support in transplanted patients with acute graft failure?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: is extracorporeal membrane oxygenation (ECMO) superior to dedicated ventricular assist device (VAD) in patients with acutely failing allograft following transplantation. Altogether, 162 papers were found using the reported search, of which 8 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Two studies provide data only for ECMO-treated patients, in three, the authors describe their experiences with Levitronix CentriMag and three studies directly compare the outcomes of ECMO and VAD support. The survival ranges from 40 to 74% in patients rescued with ECMO compared with 33-60% in patients supported with dedicated VAD. We conclude that there is insufficient evidence to prefer ECMO over VAD and the optimal modality of mechanical circulatory support (MCS) following heart transplantation should be determined by the surgeon and institutional experience and dependent on the extent and severity of myocardial dysfunction and the presence or absence of associated respiratory insufficiency.